Download a file

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description goes beyond annotations by disclosing the transfer mechanism (SCP legacy mode vs SFTP) based on the host's scpLegacy setting. This is useful behavioral context that the annotations (readOnlyHint=false, destructiveHint=false) do not provide. However, it does not mention whether the download is full or partial, any size limits, or authentication requirements. Overall, it adds some value but leaves significant behavioral aspects undisclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is short and largely free of fluff, but it redundantly states 'Download a file' twice in two sentences. It is still concise overall, with no unnecessary detail. The extra mechanism note (SCP/SFTP) is relevant and placed after the basic purpose, so the structure is acceptable.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has four parameters with no schema descriptions, no output schema, and no parameter documentation, the description is far from complete. It does not explain what the parameters mean, what the return value is, or any side effects. The addition of the transport detail is helpful but insufficient for an agent to use the tool correctly without external knowledge.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 0% description coverage for its four parameters, and the description does not compensate by explaining the meaning of path, hostId, userId, or sessionId. The agent has no clue from the description what these parameters refer to or how to populate them. This is a severe gap, as the description must carry the burden in such cases but fails to do so.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a clear verb and resource ('Downloads a file from the remote host'), making the purpose evident. However, it does not differentiate from siblings like stream_download_file or read_file, which also involve retrieving file content. The verb 'download' is more specific than 'read', but without contrasting it with those tools, the uniqueness is not explicit.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It does not mention that stream_download_file exists for streaming, or that read_file is for reading content without persisting locally. No prerequisites, exclusions, or context for selection are given; the agent is left to infer from the name alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.